A novel reduced α-Keggin type polyoxometalate coordinated to two and a half copper complex moieties: [Cu(2,2′-bipy)2][PMoVI8MoV4O40{Cu(2,2′-bipy)}2.5]·H2O

A novel reduced polyoxometalate derivative [Cu(2,2′-bipy)2][PMoVI8MoV4O40{Cu(2,2′-bipy)}2.5]·H2O 1 has been hydrothermally synthesized and characterized by IR and XPS spectra, TG analysis and single-crystal X-ray diffraction. Compound 1 crystallizes in the monoclinic system, space group P21/c, a=21.620(4) Å, b=19.070(4) Å, c=17.810(4) Å, β=109.99(3)°, V=6901(2) Å3, Z=4. The result of structure determination shows that the reduced α-Keggin polyoxoanion [PMoVI8MoV4O40]7− is capped by two divalent Cu atoms through four bridging oxo groups on two opposite {Mo4O4} faces or pits and supports a half {Cu(2,2′-bipy)} complex via the surface bridging oxygen atoms.